Mixing heads for two-component plastics are known in which the components are injected under high pressure through injection nozzles located opposite one another into a cylindrical mixing chamber, the mixture is transferred from the mixing chamber into a settling chamber arranged at a right angle to the mixing chamber and is subsequently charged, for example in free-flowing manner, into open molds (see DE-A 29 07 938). In this case axially displaceable cleaning pistons and ejection pistons are provided both in the mixing chamber and in the settling chamber, which, after the filling of a mold has been concluded--ie, at the end of the shot, are axially displaced so that they fill out the respective chambers. The mixing-chamber cleaning piston comprises longitudinal grooves located opposite one another which in the piston position sealing the mixing chamber cover the injection nozzles and establish a connection to return lines for the components.
A reduction in the turbulence prevailing in the mixture is intended to take place in the settling chamber, so that emission of the mixture from the settling chamber takes place in laminar manner.
Now, it has been shown that, particularly in the case of mixing heads for relatively large throughputs of the two-component mixture, in the case of which the diameter ot the settling chamber is designed to be correspondingly large, only an inadequate reduction of turbulence takes place, so that the stream of the mixture flowing out has a tendency to fan out. With a view to avoiding a fanned outflow stream the settling chamber has to be disproportionately extended in the axial direction.